Menu

Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Dark diversity in dry calcareous grasslands is determined by dispersal ability and stress-tolerance

Author:
  • Kersti Riibak
  • Triin Reitalu
  • Riin Tamme
  • Aveliina Helm
  • Pille Gerhold
  • Sergey Znamenskiy
  • Karin Bengtsson
  • Ejvind Rosen
  • Honor C Prentice
  • Meelis Paertel
Publishing year: 2015
Language: English
Pages: 713-721
Publication/Series: Ecography
Volume: 38
Issue: 7
Document type: Journal article
Publisher: Wiley-Blackwell

Abstract english

Temperate calcareous grasslands are characterized by high levels of species richness at small spatial scales. Nevertheless, many species from a habitat-specific regional species pool may be absent from local communities and represent the dark diversity' of these sites. Here we investigate dry calcareous grasslands in northern Europe to determine what proportion of the habitat-specific species pool is realized at small scales (i.e. how the community completeness varies) and which mechanisms may be contributing to the relative sizes of the observed and dark diversity. We test whether the absence of particular species in potentially suitable grassland sites is a consequence of dispersal limitation and/or a low ability to tolerate stress (e.g. drought and grazing). We analysed a total of 1223 vegetation plots (1 x 1 m) from dry calcareous grasslands in Sweden, Estonia and western Russia. The species co-occurrence approach was used to estimate the dark diversity for each plot. We calculated the maximum dispersal distance for each of the 291 species in our dataset by using simple plant traits (dispersal syndrome, growth form and seed characteristics). Large seed size was used as proxy for small seed number; tall plant height and low S-strategy type scores were used to characterise low stress-tolerance. Levels of small-scale community completeness were relatively low (more species were absent than present) and varied between the grasslands in different geographic areas. Species in the dark diversity were generally characterized by shorter dispersal distances and greater seed weight (fewer seeds) than species in the observed diversity. Species within the dark diversity were generally taller and had a lower tolerance of stressful conditions. We conclude that, even if temperate grasslands have high levels of small-scale plant diversity, the majority of potentially suitable species in the regional species pool may be absent as a result of dispersal limitation and low stress-tolerance.

Keywords

  • Biological Sciences

Other

Published
  • ISSN: 1600-0587
Honor C. Prentice
E-mail: honor_c [dot] prentice [at] biol [dot] lu [dot] se

Professor emerita

Biodiversity

+46 46 222 89 71

+46 73 596 83 34

E-A313

Sölvegatan 37, Lund

50